An erection is caused by an influx of blood into sponge-like regions of tissue in the penis. The increased volume of blood in the penis causes it to become rigid and to increase in length and diameter. Many males suffer from erectile dysfunction. This condition is characterized by an inability to develop or maintain an erection that is of sufficient strength or duration to allow normal sexual intercourse.
A peristaltic pump operates by compressing the exterior of a tube, causing the contents of the tube to move away from the area of compression. Such pumps have many applications in the non-medical and in the medical field.
U.S. Pat. No. 5,372,573 to Habib, which is incorporated herein by reference, describes a method of improving the flow of blood through a region of increased impedance. Blood flow is assisted in said region by means of a pump placed in or around a blood vessel supplying blood to said area, and pumping blood in the required direction. The pump comprises, in one embodiment, a housing annularly surrounding a compressible conduit, said housing containing a plurality of flexible inflatable containers mounted for contact with said conduit (e.g., a blood vessel) and means for effecting sequential inflation and deflation of said containers so as to create a peristaltic pumping effect.
U.S. Pat. No. 3,885,251 to Pedroso, which is incorporated herein by reference, describes an implantable artificial heart pump or heart assist for providing or enhancing a controlled cyclic blood flow through an artery, the pump including a tubular section secured between adjacent ends of a severed artery forming a continuous blood flow passage, and having a plurality of axially spaced but adjacent sleeves encircling this section. The sleeves are sequentially constricted about the tubular section to provide alternately pumping and suction upon the blood flowing through the section, the sleeves being energized by high and low pressure working fluid from an external or implantable power source. Where the power source is an implantable Stirling engine, pressure variations are described as being available from the gas working space, or from an oil pump in the crankcase, or from a compressor driven by the engine.
U.S. Pat. No. 3,827,426 to Page et al., which is incorporated herein by reference, describes a pump particularly suited for use as a prosthetic device in a biological system to replace a pumping component of said system; a novel electro-mechanical transducer; a method for providing a prosthetic pump in a biological system; and a method for forming an electrically actuated contractile element for use on a pump. The pump is formed of a resilient side walled chamber with exterior and interior surfaces contoured in the shape of the component to be replaced. The walls of the chamber are provided with one or more contractile elements arranged so that upon contraction of said elements the chamber will be contracted. A preferred contractile element is formed of a titanium-nickel alloy such as Nitinol selected from the class of binary equiatomic compounds of transition elements from group IV and group VIII. By arranging the Nitinol secured in a stressed orientation with respect to the chamber wall, subsequent application of current pulses to the wire are described as producing a heating of the Nitinol wire returning the wire to its original unstressed shape, thereby contracting the chamber wall to produce pumping. The pump has particular application as an artificial heart.
U.S. Pat. No. 6,023,640 to Ross, which is incorporated herein by reference, describes a method for dealing with impotency due to an inadequate volume of penis-engorging blood. The method uses electromagnetic therapy to align the nutrients of the blood in a pearl cell formation in the direction of arterial flow, which contributes, because of lessened flow resistance, to an increased volume of blood adequate for penis-engorgement.
The following patents, which are incorporated herein by reference, may be of interest:    U.S. Pat. No. 4,829,990 to Thuroff et al.    U.S. Pat. No. 4,982,731 to Lue et al.    U.S. Pat. No. 5,048,511 to Rosenbluth et al.    U.S. Pat. No. 6,706,682 to Shabsigh.
The following article, which is incorporated herein by reference, may be of interest:
Ball G et al., “A miniature peristaltic pump with electronic rate control: technical adaptation to a clinical need,” Biomed Eng. December 1974; 9(12):563-5.